CVE-2026-1999

HIGH EPSS 14.2%
Published Feb 18, 20264mo ago · Modified Jun 17, 20261w ago
7.1 CVSS 4.0
High
Find Similar
Published Feb 18, 2026 4mo ago
Last Modified Jun 17, 2026 1w ago

Description

An incorrect authorization vulnerability was identified in GitHub Enterprise Server that allowed an attacker to merge their own pull request into a repository without having push access by exploiting an authorization bypass in the enable_auto_merge mutation for pull requests. This issue only affected repositories that allow forking as the attack relies on opening a pull request from an attacker-controlled fork into the target repository. Exploitation was only possible in specific scenarios. It required a clean pull request status and only applied to branches without branch protection rules enabled. This vulnerability affected GitHub Enterprise Server versions prior to 3.19.2, 3.18.5, and 3.17.11, and was fixed in versions 3.19.2, 3.18.5, and 3.17.11. This vulnerability was reported via the GitHub Bug Bounty program.

CVSS Details

Base Score
7.1
Exploitability
Impact
Vector string
CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:N/VI:H/VA:L/SC:L/SI:H/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Attack Vector Network
Attack Complexity Low
Privileges Required Low
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
14.2% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-863 Incorrect Authorization Authorization

Affected Products 3

VendorProductVersionRange
githubenterprise_server* <3.17.11
githubenterprise_server*≥3.18.0  –  <3.18.5
githubenterprise_server*≥3.19.0  –  <3.19.2

References 3

  • docs.github.com https://docs.github.com/en/enterprise-server@3.17/admin/release-notes#3.17.11
  • docs.github.com https://docs.github.com/en/enterprise-server@3.18/admin/release-notes#3.18.5
  • docs.github.com https://docs.github.com/en/enterprise-server@3.19/admin/release-notes#3.19.2

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.